Tuesday 11 December 2012

How did our preschool garden grow? (K1 gardening)


Growth in Plants

In the middle of the summer, when I first started to plan the gardening unit for preschool science this year it occurred to me that lessons which focused on sprouting seeds didn't make much sense in the fall.

There are so few plants that you would think of sprouting in September or October in the northern hemisphere - especially this far north.  So, just as we are starting school and would like to start new growing projects the weather is turning against us and getting colder and darker every week. As this was going to be a project that went through the whole school year I knew that early spring would be a much better time to study seeds and to sprout and grow plants from seeds. 

That got me thinking that there is more than one way to grow a plant - ie. vegetative propagation -so I bought the Royal Horticultural Society's guide to Propagation Techniques and read a little bit about growing new plants from already existing plants


One of the first things that I learned is that this type of growth is possible because we are using the plant's ability to produce new organs from adventitious* cells. 

 * (Isn't that a wonderful word - adventitious - it sounds as though deep in their cells the plants are the true explorers in our world - and in a way they are - by having the ability to grow new buds and shoots from a pruned branch or stem they are creating a completely new plant from the original plant- that certainly is very adventurous !)

Thinking about growing new plants from the cuttings and stems of already existing plants also reminded me of the Redwood tree circles that you find in Santa Cruz CA - where I went to college.  And in looking up the botanical meaning adventitious on the internet I found the following definition 

Here is a short clip of a redwood tree circle:


For our preschool classes I wanted to focus during the first few months of school on this kind of vegetative growth because this was something that we could do with common houseplants and root vegetables during the fall and winter months.  Once the plants got growing they would make a nice living addition to the classroom or a new plant that students could take home with them.

 I created a series of lesson plans based on a few simple questions -

• How can we make new plants from old ones?
• What parts of a plant might be used to grow a new plant?
• What do plants need to grow?

If you work with young children - or have some young children in your family - here are some ideas for some projects that you can do with them at any time of year to learn about and observe some common ways that plants grow.  I have made a series of short slide shows to give you an idea of how we did each short project.

Idea 1.  Try growing new plants from Roots

For one lesson we investigated what parts of some common root vegetables would grow - we cut beets and carrots into slices and then observed how they grew….


If you look closely at the very end of the slideshow you can see the new stems and leaves growing from the tops of the beet and carrot.  You can use any common root vegetables - I think it works best if  still have their green tops and leaves on them but I know people who have done it with carrots that have no tops left at all.  

Idea 2. Try growing new plants from Bulbs
We also looked at bulbs - some were flowering bulbs such as hyanciths but we also did come very close observations of garlic bulbs.

I would like to do more lessons with onions and garlic in the future - what a great project to have growing in a a classroom window.  They can then be harvested and you have some great materials for some cooking activities as well.

Idea 3. Trying growing new plants from Stems
Finally, for a classic example of vegitative growth - consider taking some cuttings from some plants that you probably already have around the house or in your garden.  We took cuttings from some common herbs such as peppermint and from some house plants but here is a good starter list to choose from:

Swedish Ivy (Plectracnthus australis)
Coleus (Coleus blumei)
ANY members of the mint family Lamiaceae
English Ivy – (Hedera helix)
Wandering Jew- (Zebrina pendula or Tradescantia fluminensis)
Pothos (Pothos aureus, Rhaphidophora aurea, or Scindapsus aureus)


We tried taking cuttings just below the nodes on the stems and we treated some with rooting hormones and left some alone.   If appears to me that there was no difference and in fact the stems that were not treated with any hormone looked to be growing faster in some instances.   So, try it out for your self - it would be a good investigation to try with older students who could make careful measurements over several weeks to track the root growth.  

Coming full circle - to pumpkins again!

You may be wondering - if you read the very first post on this blog - what happened in the pumpkin patch which we planted at the beginning of the school year for our preschool gardening unit?

Well all the pumpkin and squash plants grew  and several flowered- and a few even put out small pumpkins - before it got too cold and dark.   Here is a short slideshow of the pumpkin patch over the last three month.  And now that we have the raised beds filled with soil we are thinking about putting on some cold frames to allow us to grow more plants through out the winter.   But, no matter what we do in the late winter we will be all ready for sprouting and planting pumpkin seeds.  Then we can plant the new young plants out in the raised beds in the spring.  That is the proper time to start plants from seeds!